TWI461398B - Process for continuous heterogeneously catalyzed partial dehydrogenation of at least one hydrocarbon to be dehydrogenated - Google Patents

Description

Method for continuous heterogeneously catalyzed partial dehydrogenation of at least one hydrocarbon to be dehydrogenated

The present invention relates to a method for continuous heterogeneously catalyzed partial dehydrogenation of at least one gas phase hydrocarbon to be dehydrogenated in a reaction chamber enclosed by a (material) housing, the housing being in contact with the reaction chamber And having at least one first orifice for feeding at least one initial gas stream into the reaction chamber and at least one second orifice for withdrawing at least one product gas stream from the reaction chamber, the method comprising the steps of: - continuously feeding at least An initial gas stream comprising at least one hydrocarbon to be dehydrogenated; - in the reaction chamber, passing the at least one hydrocarbon to be dehydrogenated through at least one catalyst bed disposed in the reaction chamber, and concomitantly producing At least one dehydrogenated hydrocarbon, an unconverted hydrocarbon to be dehydrogenated, and a product gas of molecular hydrogen and/or steam, partially dehydrogenated to at least one dehydrogenated hydrocarbon in an oxidative or non-oxidative manner, and - self-reacting at least one product gas stream The chamber is continuously withdrawn.

The invention also relates to apparatus for carrying out the process of the invention, and to a method of partial oxidation of at least one dehydrogenated hydrocarbon.

The term "dehydrohydrocarbon" as used in this application is intended to include hydrocarbons whose molecules contain at least two hydrogen atoms than the molecules of the hydrocarbon to be dehydrogenated (preferably "two" from the point of view of application). Further, the term hydrocarbon is intended to include a substance whose molecular system is formed only of carbon and hydrogen.

Thus, the dehydrogenated hydrocarbons in particular comprise acyclic aliphatic hydrocarbons and cyclic aliphatic hydrocarbons having one or more carbon-carbon double bonds in the molecule.

Examples of such aliphatic dehydrogenated hydrocarbons are propylene, isobutylene, ethylene, 1-butene, 2-butene and butadiene. In other words, the dehydrogenated hydrocarbon includes, in particular, a monounsaturated linear hydrocarbon (normal olefin) or a branched aliphatic hydrocarbon (for example, an isoolefin), and a cyclic olefin. Further, the dehydrogenated hydrocarbon is also intended to contain a multiolefin (e.g., a diene and a triene) having more than one carbon-carbon double bond in its molecule. However, the dehydrogenated hydrocarbon is also intended to comprise a hydrocarbon compound obtained from the alkylaromatic hydrocarbons such as ethylbenzene or cumene by dehydrogenation of the alkyl substituent. Such materials are, for example, compounds such as styrene or alpha-methylstyrene.

The dehydrogenated hydrocarbon is a starting compound which is extremely valuable for the synthesis of, for example, a functionalized radical polymerizable compound such as acrylic acid derived from propylene, or methacrylic acid obtained from isobutylene, and a polymerization product thereof. For example, the functionalized compounds can be obtained by partial oxidative dehydrogenation of hydrocarbons. However, dehydrogenated hydrocarbons are also suitable for the preparation of compounds such as methyl tert-butyl ether (a subsequent product of isobutylene which is suitable, for example, as a fuel additive for increasing the number of octanes). The dehydrogenated hydrocarbon itself can also be used for polymerization.

Suitable hydrocarbons to be dehydrogenated herein may especially be non-cycloalkanes and cycloalkanes, but may also be olefins (the number of carbon-carbon double bonds will increase) (for example, n-butene may be mentioned as uneven The phase catalytic partial dehydrogenation is butadiene).

In other words, the term "hydrocarbon to be dehydrogenated" in the present patent application includes, for example, a stoichiometric hydrocarbon of C _n H _2n+2 , wherein: n>1 to n 20, and a stoichiometric C _n H _2n hydrocarbon, wherein: n > 1 to n 20, and a stoichiometric hydrocarbon of C _n H _2n-2 , wherein: n>2 to n 20, and n is an integer; especially C ₂ alkane to C ₁₆ alkane, such as ethane, propane (to propylene), n-butane, isobutane (to isobutene), n-pentane, isopentane, n-hexane, n-Heptane, n-octane, n-decane, n-decane, n-undecane, n-dodecane, n-tridecane, n-tetradecane, n-pentadecane and n-hexadecane.

However, in particular, all statements herein apply to C ₂ - to C ₈ -alkanes as hydrocarbons to be dehydrogenated, and are extremely suitable for C ₂ to C ₄ hydrocarbons (especially alkanes). In other words, the hydrocarbons to be dehydrogenated herein are especially ethane, propane, n-butane and isobutane, and are also 1-butene and 2-butene.

The method for the preparation of dehydrogenated hydrocarbons as described in the introduction is known to us (see, for example, WO 03/076370, DE-A 10 2004 032 129, EP-A 731 077, WO 01/96271, WO 01/96270 DE-A 103 16 039, WO 03/011804, WO 00/10961, EP-A 799 169 and DE-A 102 45 585).

In principle, the method for preparing dehydrogenated hydrocarbons by heterogeneously catalyzing partial dehydrogenation of at least one hydrocarbon to be dehydrogenated can be divided into two groups: oxidative heterogeneously catalyzed partial dehydrogenation and non-oxidative heterogeneity. The phase catalytic part is dehydrogenated. Non-oxidative heterogeneously catalyzed partial dehydrogenation is achieved without the action of molecular oxygen compared to oxidative heterogeneously catalyzed partial dehydrogenation. In other words, the molecular hydrogen to be removed from the hydrocarbon to be dehydrogenated is rapidly desorbed by molecular hydrogen, and is not at least partially oxidized to water by molecular oxygen in a subsequent step. Therefore, in all cases, the thermal properties of non-oxidative dehydrogenation are endothermic. In contrast, in the oxidative heterogeneously catalyzed partial dehydrogenation, the molecular hydrogen to be removed from the hydrocarbon to be dehydrogenated is desorbed by the action of molecular oxygen. It can be quickly separated from the produced water (H ₂ O) (this condition is also referred to as heterogeneously catalyzed oxidative dehydrogenation; its thermal properties are exothermic in all cases). However, it can also be expressed as molecular hydrogen (ie, non-oxidizing or conventional), and then it can be partially or completely oxidized to water (H ₂ O) via molecular oxygen in a subsequent step (depending on subsequent hydrogen combustion). Depending on the extent, the total thermal properties can be endothermic, exothermic or neutral).

All of the above heterogeneously catalyzed partial dehydrogenation of the dehydrogenated hydrocarbons is common in that they are all carried out at relatively high reaction temperatures. The general reaction temperature can be 250 ° C, usually 300 ° C, often 350 ° C, or 400 ° C, or 450 ° C, or 500 ° C.

Moreover, during long-term operation of continuous heterogeneously catalyzed partial dehydrogenation, as operating time increases, higher reaction temperatures are typically required to maintain dehydrogenation conversion in a single pass through the reaction chamber. This is usually due to the fact that as the operating time is extended, the degree of irreversible deactivation of the catalyst used increases. In other words, even when the continuous operation is temporarily interrupted a plurality of times (the term "continuously" is intended to encompass the mode of operation herein), in order to reactivate (regenerate) the catalyst used by means of an appropriate manner, as the total operation time of the method is extended, The initial activity of the catalyst increases over the time reached during the total operating time. A corresponding increase in reaction temperature counteracts this fact.

A disadvantage of the high reaction temperature is that the degree of influence of the undesired side reaction increases with an increase in the reaction temperature with respect to the desired target reaction (hydrocarbon to be dehydrogenated → dehydrogenated hydrocarbon). One of the undesirable side reactions is, for example, the thermal decomposition of hydrocarbons to be dehydrogenated and/or dehydrogenated hydrocarbons into hydrocarbons which generally have a lower number of carbon atoms.

The materials proposed for the housing in the method described in the opening of the prior art are various steels. The housing material proposed in WO 03/076370, for example in its working example, is aluminized, aluminized and/or aluminized on the side of the housing which is in contact with the reaction chamber (ie coated with aluminum or coated with aluminum oxide or coated). Steel with aluminum and alumina). The composition of this steel is not further described in WO 03/076370. The same introduction is made in WO 03/011804. In addition, it has been proposed to use sulfides in the initial gas stream as a possible alternative to achieve the purpose of passivating the side of the housing in contact with the reaction chamber.

However, the disadvantage of aluminizing or aluminizing and/or aluminizing is that it can only be carried out at an extremely high cost, on an industrial scale. The disadvantage of using sulfides in the initial gas stream is first of all for this purpose, and secondly the usage generally has a detrimental effect on the lifetime of the catalyst used for the heterogeneously catalyzed partial dehydrogenation and/or if necessary The lifetime of the catalyst used for the heterogeneously catalyzed partial oxidation of the dehydrogenated hydrocarbons has an adverse effect.

The teachings of DE-A 10 2004 032 129 do not enumerate the above disadvantages, and the case material proposed in the comparative example thereof is an uncoated stainless steel of DIN material number 1.4841. The housing material proposed in a similar manner in DE-A 10 2005 051 401 and DE-A 10 2005 052 917 is a Si-containing stainless steel or a steel of a very broad meaning, for example DIN type 1.4841.

However, internal investigations have surprisingly found that steel, as a material on the side of the shell that contacts the reaction chamber, is capable of catalyzing the thermal decomposition of hydrocarbons and/or dehydrogenated hydrocarbons to be dehydrogenated, so that even at relatively low reaction temperatures Become unobtrusive in a way that is undesired. This case is particularly applicable to stainless steel of DIN material No. 1.4841 having the following elemental composition: 24 to 26 wt% of Cr; 19 to 22 wt% of Ni; 1.5 to 2.5 wt% of Si; 0 to 0.11 wt% of N; 0 to 0.2 wt% of C; 0 to 2 wt% of Mn; 0 to 0.045 wt% of P; 0 to 0.015 wt% of S; and in addition, iron and the impurities produced in the manufacture, each percentage is based on the total weight.

Generally, the nitrogen content of this type of steel is significantly less than 0.11% by weight, and therefore the steel manufacturer generally does not elaborate on this.

During the internal investigation, it was also found that the catalytic effect of steel on the thermal decomposition of hydrocarbons to be dehydrogenated and/or dehydrogenated hydrocarbons depends on the elemental composition of the steel used.

The disadvantages of thermal decomposition of hydrocarbons to be dehydrogenated and/or dehydrogenated hydrocarbons are not only that thermal decomposition reduces the selectivity of the target product, but also that the decomposition products produced at high temperatures are potential formations of elemental carbon (coke), elemental carbon. (Coke) is deposited on the surface of the catalyst used for heterogeneously catalyzed partial dehydrogenation so that it is inactivated at an increased rate and at least partially irreversibly. In addition, thermal decomposition of the hydrocarbon proceeds substantially in an endothermic manner and recovers the heat of the actual target reaction.

Accordingly, it is an object of the present invention to provide a method as described in the opening paragraph which uses steel suitable for the surface of the casing on the side of the casing contacting the reaction chamber, which is even in a non-aluminized form and also in the initial gas flow. Sulfide-free, this steel catalyzes the thermal decomposition of hydrocarbons to be dehydrogenated and/or dehydrogenated hydrocarbons in a manner less obvious than stainless steel of DIN material number 1.4841.

Thus, a method for continuous heterogeneously catalyzed partial dehydrogenation of at least one gas phase hydrocarbon to be dehydrogenated in a reaction chamber enclosed by a (material) shell is disclosed, the shell contacting the reaction chamber (ie, contacting the reaction gas, that is, the hydrocarbon to be dehydrogenated and the dehydrogenated hydrocarbon) and having at least one first hole for feeding at least one initial gas stream into the reaction chamber and at least one of the at least one product gas stream from the reaction chamber a second hole extracted, the method comprising the steps of: - continuously feeding at least one initial gas stream comprising at least one hydrocarbon to be dehydrogenated; - passing the at least one hydrocarbon to be dehydrogenated through at least one in the reaction chamber a catalyst bed placed in the reaction chamber, accompanied by a product gas comprising the at least one dehydrogenated hydrocarbon, unconverted hydrocarbon to be dehydrogenated, and molecular hydrogen and/or vapor, partially oxidized or non-oxidized Hydrogen is at least one dehydrogenated hydrocarbon, and - at least one product gas stream is continuously withdrawn from the reaction chamber; wherein: the surface of the shell on its side contacting the reaction chamber is at least partially composed of steel S having the following elements Made and made The layer thickness is at least 1 mm (in each case, indicated by the reaction chamber at a right angle to the tangent drawn from the specific contact point on the side contacting the reaction chamber): 18 to 30 wt% Cr; 9 to 36 wt % of Ni; 1 to 3 wt% of Si; 0.1 to 0.3 wt% of N; 0, preferably 0.03 to 0.15 wt% of C; 0 to 4 wt% of Mn; 0 to 4 wt% of Al; 0 to 0.05 wt% of P; 0 to 0.05 wt% of S; and 0 to 0.1, preferably >0 to 0.1 and more preferably 0.03 to 0.08 wt% of one or more rare earth metals, and in addition to the elements, also contains Fe and impurities produced in the production, each percentage is (steel Total weight meter.

In the context of the above content, generally when the N content 0.11 wt%, slightly better 0.12 wt%, preferably 0.13 wt%, better 0.14 wt% and excellent 0.15 wt% is preferred. More preferably, the N content is from 0.15 wt% to 0.18 wt%. More preferably, the preferred ranges specified above are used in combination.

Advantageously, according to the invention, the total amount of impurities produced in the manufacture is generally calculated as described above. 1 wt%, preferably 0.75 wt%, better 0.5 wt% and best 0.25 wt%. However, the total amount of impurities produced in steel manufacturing is generally 0.1 wt%. The other components in the steel are some of the alloying constituents that determine their properties compared to the impurities produced in the manufacturing process. This applies in particular to the elements Cr, Ni, Si, N and C.

Rare earth metals include cerium (Ce), praseodymium (Pr), neodymium (Nd), strontium (Pm), strontium (Sm), strontium (Eu), strontium (Gd), strontium (Tb), strontium (Dy), strontium (Dy) Ho), 铒 (Er), 銩 (Tm), 镱 (Yb) and 鑥 (Lu). A preferred rare earth metal of the present invention is Ce. Preferably, according to the invention, the corresponding steel S thus has 0 to 0.1 wt% of Ce or Ce and one or more rare earth metals other than Ce (especially La, Nd and/or Pr).

Advantageously, the surface of the casing on its side contacting the reaction chamber is made of a corresponding steel having a total surface area of at least 10%, preferably at least 20% or at least 30%, more preferably at least 40% or At least 50%, more advantageously at least 60% or at least 70%, further preferably at least 80% or at least 90%, and most preferably at least 95% or at least 100%, is formed to have a layer thickness of at least 1 mm. According to the invention, advantageously d is at least 2 mm, or at least 3 mm, or at least 4 mm, or at least 5 mm. It should be understood that d can also be from 5 mm to 30 mm, or up to 25 mm, or up to 20 mm, or up to 15 mm, or up to 10 mm. Most preferably, the housing of the closed reaction chamber of the method of the invention is entirely made of steel of the invention or of at least 80% by weight, preferably at least 90% by weight or at least 95% by weight of the steel of the invention production. According to the present invention, preferably, the (tube) channel for transporting at least one initial gas stream to the reaction chamber and at least one product gas stream exiting the reaction chamber is made of the steel S of the present invention, or at least on the side where it contacts the gas. steel. Of course, the (tube) channels (especially their output pipes) can also be made of other steels, for example made of steel of DIN material number 1.4910 or 1.4941 or 1.4541 or 1.4841. It is extremely suitable to use the steel S of the present invention, especially when the reaction gas has When the material at a temperature of 450 ° C is in contact.

For correct and safe operation, the above-mentioned pipes are preferably equipped with means for compensating for longitudinal expansion effects (for example, which may occur due to temperature changes), and it is advantageous to use a compensator which is characterized by a lateral mode.

These compensators, which generally have a multi-layer design, can be made of the same material as the pipe itself. However, particularly advantageous embodiments are those having inner tubular members, preferably made of the steel S of the invention (generally gas permeable rigid inner tubes and gas impermeable elastic outer sleeves (gas impermeable elastomer) The outer tube)) is in contact with the gas to be transported and suitably has a gas permeable expansion joint and an outer gas impermeable elastic corrugated member, the outer gas impermeable elastic corrugated member being at least partially mechanically Made of pressure and heat-pressible material, for example from material 1.4876 (according to VdT V-Wb 434 named) or 1.4958/1.4959 (named according to DIN 17459) or INCOLOY 800 H or 800 HT, or nickel based material 2.4816 (instead of the named alloy 600) or 2.4851 (instead of the named alloy 601).

According to the present invention, preferably, the steel S corresponding to the present invention has the following elemental composition: 18 to 26 wt% of Cr; 9 to 36 wt% of Ni; 1 to 2.5 wt% of Si; 0.1 to 0.3 wt% of N; 0, preferably 0.03 to 0.15 wt% of C (regardless of other contents); 0 to 3 wt% of Mn; 0 to 4 wt% of Al; 0 to 0.05 wt% of P; 0 to 0.05 wt% of S; and 0 to 0.1, preferably >0 to 0.1 and more preferably 0.03 to 0.08 wt% (all other contents are not considered in all cases) one or more rare earth metals (preferably Ce or Ce and one or more other rare earth metals), and In addition to this, it also contains Fe and impurities generated in the production; each percentage is based on the total weight of (steel).

More advantageously, the corresponding steel S of the present invention has the following elemental composition: 20 to 25 wt% of Cr; 9 to 20 wt% or (regardless of other content) preferably of 15 wt% of Ni; 1.4 to 2.5 wt% Si; 0.1 to 0.3 wt% of N; 0, preferably (regardless of other content) 0.03 to 0.15 wt% of C; 0 to 3 wt% of Mn; 0 to 4 wt% of Al; 0 to 0.05 wt% of P; 0 to 0.05 wt% of S; and 0 to 0.1, preferably >0 to 0.1 and more preferably 0.03 to 0.08 wt% (other contents are not considered in all cases) one or more rare earth metals (preferably Ce or Ce and one or more other rare earth metals), In addition, it also contains Fe and impurities produced in the production; each percentage is based on the total weight of (steel).

More preferably, the corresponding steel S of the present invention has the following elemental composition: 20 to 22 wt% of Cr; 10 to 12 wt% of Ni; 1.4 to 2.5 wt% of Si; 0.12 to 0.2 wt% of N; 0, preferably (without considering all other contents) 0.05 to 0.12 wt% of C; 0 to 1 wt% of Mn; 0 to 2, preferably (regardless of all contents) 0 wt% of Al; 0 to 0.045 wt% of P; 0 to 0.015 wt% of S; and 0 to 0.1, preferably >0 to 0.1 and more preferably 0.03 to 0.08 wt% (without considering all other contents in each case) one or more rare earth metals (preferably Ce or Ce and one or more other rare earth metals), In addition, it also contains Fe and impurities generated in the production; each percentage is based on the total weight of (steel).

Quite generally, in the context of all compositions that are advantageous or preferred as described above, when the N content 0.11 wt%, slightly better 0.12 wt%, preferably 0.13 wt%, better 0.14 wt% and good It is preferably 0.15 wt%. It is especially preferred that the N content in all cases is from 0.15 to 0.18 wt%. Advantageously, all of the ranges described as preferred in each case are used in combination.

In particular, the gist of the present invention is that the preferred steel composition S has been selected to advantageously find that it is not only related to the undesired catalysis of the corresponding steel.

Or, in particular, steels of other alternative materials have been found to be advantageous in terms of their mechanical compressibility and their corrosion stress and other wear stresses, and other preferred ranges should be considered. This fact is crucial, especially when the housing is made substantially entirely of the selected steel S.

For example, the steel S used should also have a low brittleness tendency under the conditions used in the heterogeneously catalyzed partial dehydrogenation. This phenomenon is particularly the case at the high reaction temperatures typically used in the process of the invention. When the reaction temperature and / or catalyst regeneration temperature is 400 ° C to 900 ° C, or 500 ° C to 800 ° C, or 550 ° C to 750 ° C, or 600 ° C to This is especially true at 700 °C. The above requirements have also been made in view of the fact that the heterogeneously catalyzed partial dehydrogenation of the present invention is preferably carried out at a working pressure of 1 atm or more. In other words, the steel S used in accordance with the invention should also be suitable for use as a pressure vessel material. Furthermore, the creep strength and thermal stability characteristics of the selected steel of the present invention should be satisfactory under the conditions of the process of the present invention. The same should be true for its rust resistance and coking tendency. A favourable choice should also be made to consider that the selected steel whiskers can be processed in an advantageous manner. This means in particular that it can be processed by welding techniques, which is not possible in the case of aluminizing the steel before processing it without damaging the aluminization. However, the post-process aluminization can only be performed on an industrial scale, at a very high cost and with inconvenience, if still enforceable. The requirements for corrosion resistance are critical, in particular from the fact that the dehydrogenated hydrocarbons formed in the process of the invention are partially oxidized under heterogeneous catalysis in a process subsequent to the process of the invention (with Hydrocarbons that are not dehydrogenated are particularly advantageous). When the desired partial oxidation product is subsequently removed from the partially oxidized product gas mixture, the residual gas containing the hydrocarbon to be dehydrogenated and the oxygenate is usually still present, and is advantageous for further conversion of the hydrocarbon to be dehydrogenated. It is at least partially recycled back to the process of the invention. However, the corrosive effect can be attributed to the overwhelming majority of all oxygenates (eg, acrolein, acrylic acid, methacrolein, methacrylic acid, H ₂ O, O ₂ , CO _{2 ,} etc.).

Steel S suitable for use in the present invention can be made in a manner known per se. See, for example, the review in the following literature: Enzyklop Die Naturwissenschaft und Technik [Encyclopedia of Natural Science and Technology], Verlag moderne Industrie, 1976, entitled "Stahlbegleiter", "Eisen" and "Eisen und Stahl"["Steelconstituents","Iron" and "Iron and Steel"] Or Ullmanns Encyclop Die der technischen Chemie [Ullmann's Encyclopedia of Industrial Chemistry], Verlag Chemie, 4th edition, Volume 3, Verfahrenstechnik II und Reaktionsapparate [Process Technology II and Reaction Apparatus], "Werkstoffe in der chemischen Industrie" chapter ["Materials in the Chemical Industry"].

Steels suitable for use in the present invention are, for example, steels of EN material numbers 1.4818, 1.4835 and 1.4854, of which steels of material number 1.4835 are particularly preferred. Steels of DIN material numbers 1.4891 and 1.4893 are also suitable for use in the process of the invention, preferably with steel of material number 1.4893. The steels of ASTM/UNS material numbers S 30415, S 30815 and S 35315 are also suitable for use in the process of the invention, according to which the steels having material number S 30815 are preferred. Steels having SS material numbers 2372, 2361 and 2368 are also suitable for use in the process of the invention, with the latter being preferred in accordance with the invention.

The above steels and other steels suitable for use in the present invention are also commercially available. For example, SE-774 22 Avesta, Outokumpu Stainless AB of Sweden sells the above steel, with the proprietary names 153 MA ^TM , 253 MA And 353 MA According to the invention, 253 MA Especially beneficial. D-47794 Krefeld, Germany's ThyssenKrupp Nirosta GmbH also sells alloy stainless steel THERMAX 4835 is particularly advantageous in accordance with the present invention.

Therefore, the steel S suitable for the present invention comprises, in particular, a steel having the following composition: I. 18.5 wt% of Cr; 9.5 wt% of Ni; 1.3 wt% of Si; 0.15 wt% of N; 0 to 0.05 wt% of C; 0 to 1 wt% of Mn; 0 to 0.045 wt% of P; 0 to 0.015 wt% of S, and 0 to 0, 1, preferably > 0 to 0.1 and more preferably 0.03 to 0.08 wt% of one or more rare earth metals (preferably Ce or Ce and one or more other rare earth metals); and in addition, Fe is also included And impurities produced in the manufacture; each percentage is based on the total weight.

II. 21 wt% of Cr; 11 wt% of Ni; 1.4 to 2.5 wt% of Si; 0.17 wt% of N; 0.09 wt% of C; 0 to 1 wt% of Mn; 0 to 0.045 wt% of P; 0 to 0.015 wt% of S, and 0 to 0.1, preferably >0 to 0.1 and more preferably 0.03 to 0.08 wt% of one or more rare earth metals (preferably Ce or Ce and one or more other rare earth metals); and in addition, Fe is also produced Impurities produced in the process; each percentage is based on the total weight.

III. 24 to 26 wt% of Cr; 34 to 36 wt% of Ni; 1.2 to 2.0 wt% of Si; 0.12 to 0.2 wt% of N; 0.04 to 0.08 wt% of C; 0 to 2.0 wt% of Mn; 0 to 0.045 wt% of P; 0 to 0.015 wt% of S, and 0 to 0.1, preferably >0 to 0.1 and more preferably 0.03 to 0.08 wt% of one or more rare earth metals (preferably Ce or Ce and one or more other rare earth metals); and in addition, Fe is also produced Impurities produced in the process; each percentage is based on the total weight.

Of course, the steel S suitable for use in the present invention can also be used in the process of the invention in aluminized, aluminized and/or aluminized form, especially on the side where it contacts the reaction chamber. It has been found to be particularly advantageous in this form to provide only a slight catalytic effect on thermal decomposition when the aluminization is damaged, for example due to manufacturing, or when damage occurs.

When the casing in the method of the present invention is not completely made of steel suitable for the present invention, but the surface of the casing on its side contacting the reaction chamber is only partially or completely formed from the steel to the minimum layer thickness of the present invention. (for example, because of economic feasibility, it may be adapted to produce a surface of the casing on its side contacting the reaction chamber only in the presence of a particularly high temperature in the reaction chamber, or indeed only from the steel of the invention The surface of the minimum layer thickness of the present invention is possible by a simple method such as electroplating (for example, roll plating or blast plating or compression welding plating), that is, at the point or all The steel of the present invention is applied as a covering material on the surface of another substrate (e.g., another steel) and adhered to the substrate, for example, by pressing or rolling or bonding or bonding.

The process of the invention is advantageous, in particular when the at least one initial gas stream comprises steam as an inert diluent gas (for example 1% by volume) and/or molecular oxygen as a reactant (eg 0.1 or 0.5% by volume). However, it is also advantageous when the at least one initial gas stream comprises steam and/or molecular oxygen as impurities. It is also advantageous when steam is formed as a reaction product during the heterogeneously catalyzed partial dehydrogenation of the present invention. This is especially true when the process of the invention uses the recycle gas or circulation process set forth in WO 03/076370. However, the process of the invention is particularly advantageous not only when the at least one initial gas stream comprises residual gases produced by partial oxidation of the dehydrogenated hydrocarbons formed in the process of the invention, but also downstream of the process of the invention The material (along with the hydrocarbon to be dehydrogenated) remains when the target product is removed from the partially oxidized product gas mixture and contains oxygenates.

Quite often, at least one of the catalyst beds disposed within the reaction chamber can be a fluidized bed or a moving or fixed bed. Of course, the fluidized bed may be present in the reaction chamber in combination with, for example, a fixed bed, or a moving bed and a fixed bed. Preferably, at least one of the catalyst beds of the method of the present invention comprises a fixed catalyst bed, in accordance with the present invention.

In this context, it should be understood that the loading of the catalyst bed of the catalytic reaction step is quite generally meant to mean a standard liter of reaction gas (=l(STP)) per hour of transport through a one liter catalyst bed (eg, a fixed catalyst bed); The amount of reaction gas in liters in standard conditions (0 ° C, 1 atm). However, the load may also be based only on one component of the reaction gas. In his case, this is the composition of l (STP) / l. The speed of h is transmitted per hour through a one liter catalyst bed (the bed of pure inert material is not counted in the fixed catalyst bed). This load may also be based only on the amount of catalyst present in a catalyst bed comprising an actual catalyst diluted with an inert material (this is explicitly set forth below).

Herein, it should be understood that complete oxidation (combustion) of dehydrogenated hydrocarbons and/or hydrocarbons to be dehydrogenated means that the entire amount of carbon present in the hydrocarbon is converted to carbon oxides (CO, CO ₂ ). As used herein, the term partial oxidation encompasses all different conversions of dehydrogenated hydrocarbons and/or hydrocarbons to be dehydrogenated under the reaction of molecular oxygen. The additional reaction of ammonia is characteristic of ammoxidation, which is also encompassed by the term partial oxidation.

As used herein, it is understood that an inert gas generally means a reaction gas component that is substantially chemically inert under appropriate reaction conditions, and each inert reaction gas component alone exceeds 95 mol%, preferably more than 97 mol%. To a degree or more than 99 mol%, it remains chemically unchanged. Examples of typical inert diluent gases are, for example, N ₂ , H ₂ O, CO ₂ , rare gases such as Ne and Ar, mixtures of such gases, and the like.

When the process of the present invention is a heterogeneously catalyzed oxidative dehydrogenation process (e.g., propane dehydrogenation to propylene), the source of molecular oxygen required may be air, pure molecular oxygen or molecular oxygen-enriched air.

Dehydrogenation (C-H splitting) is more cumbersome in kinetics than thermal decomposition or cleavage (C-C splitting) and therefore requires the method of the present invention to be carried out with a selective dehydrogenation solid state catalyst. Due to the selective catalyst and the use of the reaction chamber of the present invention, only a small amount of by-products such as methane, ethylene and ethane are formed in the case of the heterogeneous catalytic dehydrogenation of the propane of the present invention.

Therefore, it should be understood that the dehydrogenation catalyst herein particularly means a shaped body whose longest dimension (the longest straight line connecting the two points present on the surface of the shaped body) is 0.1 or 1 to 30 mm, preferably 1 to 20 mm. And more preferably 1 to 10 mm or 1 to 5 mm, and in the following experiment, a single pass of the reaction mixture through the reaction tube, which can dehydrogenate at least 5 mol% of the propane present in the reaction gas to propylene: The reaction tube made of the steel of EN material No. 1.4835A used in the present invention was fed as follows, which had a wall thickness of 2 mm, an inner diameter of 35 mm and a length of 80 cm. Place 50 ml of the appropriate dehydrogenation catalyst bed in the center of the reaction tube. In each case, the reaction tube was filled with a bed of talc balls (inert spheres) having a sphere diameter of 1.5 mm to 2.5 mm above and below the shaped contact media bed. A grid supports the entire bed. The entire length of the reaction tube was maintained at a temperature of 550 ° C from the outside. A mixture of propane and steam in a volume ratio of 2 (propane) to 1 (steam) is fed into the reaction tube, and the propane load of the catalyst bed is 1000 l (STP) / l. h. The initial gas stream has been preheated to a temperature of 550 °C. It is especially preferred that the cumulative selectivity of the formation of ethane, ethylene and methane by-products under the above-mentioned boundary conditions is calculated as converted propane. 5 mol% dehydrogenation catalyst.

The heterogeneously catalyzed oxidative dehydrogenation process of the present invention can in principle be carried out, for example, as described in the following documents, for example, US-A 4,788,371; CN-A 1073893; Catalysis Letters 23 (1994), 103-106, W. Zhang, Gaodeng Xuexiao Huaxue Xuebao, 14 (1993) 566, Z. Huang, Shiyou Huagong, 21 (1992) 592; WO 97/36849; DE-A 197 53 817; US-A 3, 862, 256; US-A 3, 887, 631; DE-A 195 30 454; US-A 4,341,664; J. Catalysis 167, 560-569 (1997), J. Catalysis 167, 550-559 (1997), Topics in Catalysis 3 (1996) 265-275; US 5,086,032; Catalysis Letters 10 (1991) , 181-192; Ind. Eng. Chem. Res. 1996, 35, 14-18; US 4, 255, 284; Applied Catalysis A: General, 100 (1993), 111-130; J. Catalysis 148, 56-67 (1994 ), V.Cort s Corber n and S.Vic Bell n (eds.), New Developments in Selective Oxidation II, 1994, Elsevier Science BV, pp. 305-313, 3 ^rd World Congress on Oxidation Catalysis, RK Grasselli, STOyama, AMGaffney and JELyons (ed.), 1997, Elsevier Science BV, 375ff pages or DE-A 198 37 520; DE-A 198 37 517; DE-A 198 37 519 and DE-A 198 37 518, which use heterogeneously catalyzed partial oxidative dehydrogenation of propane as an example. In this case, as previously mentioned, the source of oxygen used may be, for example, air. However, in addition to the inert gas, the oxygen source used has a molecular oxygen range of usually at least 90 mol%, and in many cases, the molecular oxygen has a range of at least 95 mol%.

The catalyst suitable for heterogeneously catalyzed oxidative dehydrogenation is not particularly limited. Suitable oxidative dehydrogenation catalysts are all of the catalysts known to those skilled in the art and are capable of, for example, oxidizing propane to propylene. In particular, all of the oxidative dehydrogenation catalysts described in the above references can be used. Suitable catalysts are, for example, oxidative dehydrogenation catalysts comprising MoVNb oxide or vanadium ruthenate (if applicable) and a promoter. An example of a preferred oxidative dehydrogenation catalyst is a catalyst comprising a metal oxide I mixed with Mo, V, Te, O and X as a main component, wherein X is at least one selected from the group consisting of ruthenium, osmium, tungsten, titanium, Aluminum, zirconium, chromium, manganese, gallium, iron, lanthanum, cobalt, lanthanum, nickel, palladium, platinum, rhodium, iridium, boron, indium, lanthanum, cerium, sodium, lithium, potassium, magnesium, silver, gold and lanthanum Elements (see also EP-A 938463 and EP-A 167109 for this subject). Other particularly suitable oxidative dehydrogenation catalysts are the multimetal oxide composition or catalyst A (referred to herein as multimetal oxide composition II) and the touch of DE-A 19838312 in DE-A-197 53 817. The above mentioned documents are particularly advantageous for the preferred multimetal oxide composition or catalyst A. Accordingly, the active composition suitable for the heterogeneously catalyzed oxidative dehydrogenation of the present invention comprises a multimetal oxide composition of the formula III: M ¹ _a Mo _1-b M ² _b O _x (III) wherein: M ¹ = Co, Ni, Mg, Zn, Mn and/or Cu; M ² = W, V, Te, Nb, P, Cr, Fe, Sb, Ce, Sn and/or La; a = 0.5 to 1.5; b = 0 to 0.5; and x = a number determined by the valence and frequency of the element other than oxygen in (III). It can be prepared and shaped as described in DE-A 102 45 585.

For the heterogeneous catalytic oxidative dehydrogenation of, for example, propane, the reaction temperature is preferably in the range of from 200 to 600 ° C, especially in the range of from 250 to 500 ° C, more preferably from 350 to 440 ° C, in the case of using a new catalyst. Within the scope. The working pressure is preferably in the range of from 0.5 to 10 bar, especially in the range of from 1 to 10 bar, more preferably in the range of from 1 to 5 bar. It has been found to be particularly advantageous to have a working pressure above 1 bar, for example 1.5 to 10 bar. In general, heterogeneously catalyzed oxidative dehydrogenation of propane is achieved on a fixed catalyst bed. The latter are suitably introduced (usually placed on a gas permeable grid) such as a salt bath cooled tube bundle reactor (for example as described in EP-A 700 893 and EP-A 700 714 and the references cited in these documents). In the tube (the tube wall and the two nozzles together form a housing contacting the reaction chamber, the inside of the tube is a reaction chamber, and the tube wall is preferably made entirely of the steel of the present invention). The initial gas flow is fed into the tube inlet. The average residence time of the reaction gas in the catalyst bed is suitably from 0.5 second to 20 seconds. The ratio of propane to oxygen varies with the desired conversion and the selectivity of the catalyst. The ratio is suitably in the range of 0.5:1 to 40:1, particularly preferably in the range of 1:1 to 6:1, and more preferably in the range of 2:1 to 5:1. In general, the propylene selectivity decreases as the propane conversion increases. Therefore, it is preferred to carry out the propane-propylene reaction in such a manner that a relatively low conversion of propane is achieved at a high selectivity of propylene. More preferably, the conversion of propane is in the range of from 5 to 40 mol%, usually in the range of from 10 to 30 mol%. In the present context, the term "propane conversion" means the proportion of the propane fed into the propane which is converted in a single pass through the reaction tube. In general, the selectivity for propylene formation is from 50 to 98 mol%, more preferably from 80 to 98 mol%, and the term "selectivity" means the number of moles of propylene obtained per mole of converted propane, expressed as Percent of moles. In the reaction tube, the reaction temperature generally goes to a maximum.

In general, the initial gas stream used in the heterogeneously catalyzed oxidative dehydrogenation of propane comprises from 5 to 95 mol% propane (based on 100 mol% of the initial gas). In addition to propane and oxygen, the initial gas used for heterogeneously catalyzed oxidative dehydrogenation may also contain other components, especially inert components such as carbon dioxide, carbon monoxide, nitrogen, noble gases, such as present in crude propane (for use in this The propane source of the process of the invention is generally other hydrocarbons and/or propylene in the crude propane as taught in DE-A 10 245 585 or DE-A 10 2005 022 798. Heterogeneous catalytic oxidative dehydrogenation can also be carried out in the presence of a diluent such as steam.

Heterogeneous catalytic oxidative dehydrogenation of, for example, propane can be carried out using any desired reactor sequence known to those skilled in the art. For example, heterogeneously catalyzed oxidative dehydrogenation can be carried out in a single reactor or in a set of two or more reactors, if applicable, between the reactors.

The product gas of the heterogeneously catalyzed propane dehydrogenation of the present invention may contain the following components as possible components, for example, propylene (as a target product, that is, a dehydrogenated hydrocarbon), propane (as an unconverted hydrocarbon to be dehydrogenated), carbon dioxide , carbon monoxide, water, nitrogen, oxygen, ethane, ethylene, methane, acrolein, acrylic acid, ethylene oxide, butane (such as n-butane or isobutane), acetic acid, formaldehyde, formic acid, propylene oxide and butyl Alkene (such as butene-1). Ethane, ethylene and methane are especially possible thermal decomposition products of propane. In general, the product gas obtained by the heterogeneously catalyzed oxidative dehydrogenation of propane of the present invention comprises, in each case, 100% of product gas: 5 to 10 mol% of propylene, 0.1 to 2 mol% of carbon monoxide, and 1 to 3 mol. % carbon dioxide, 4 to 10 mol% water, 0 to 1 mol% nitrogen, 0.1 to 0.5 mol% acrolein, 0 to 1 mol% acrylic acid, 0.05 to 2 mol% acetic acid, 0.01 to 0.05 mol% formaldehyde, 1 to 5 mol % oxygen, 0.1 to 10 mol% of the other above ingredients, and the remainder of the propane.

According to the present invention, the heterogeneously catalyzed oxidative dehydrogenation of hydrocarbons other than propane to be dehydrogenated can be carried out in the same manner as described above for the oxidative dehydrogenation of propane. Such suitable hydrocarbons to be oxidatively dehydrogenated are, in particular, butane (dehydrogenated to butene (especially isobutane dehydrogenated to isobutylene) and/or butadiene) and butene (dehydrogenated to butadiene).

Regeneration of the catalyst for the partial heterogeneous catalytic oxidative dehydrogenation of propane, for example, in the case of partial oxidation catalysts in the documents DE-A 103 51 269, DE-A 103 50 812 and DE-A 103 50 822 Said to proceed.

When the heterogeneously catalyzed partial dehydrogenation of the present invention is not oxidative dehydrogenation, it generally comprises a conventional heterogeneous catalytic dehydrogenation, that is, molecular hydrogen is formed at least as an intermediate, and is in oxidative properties. In the case of heterogeneously catalyzed partial dehydrogenation, water is at least partially combusted with molecular oxygen in a subsequent step.

Catalysts suitable for the heterogeneously catalyzed dehydrogenation of the hydrocarbons to be dehydrogenated in the process of the invention are in principle all dehydrogenation contacts known in the prior art for conventional heterogeneous catalytic dehydrogenation. Media. They can be broadly classified into two categories, specifically, those having oxidizing properties (such as chromium oxide and/or aluminum oxide) and generally relatively precious metals (such as platinum) deposited on at least one of general oxidative supports. Composition of their substances. Dehydrogenation catalysts which can be used include WO 01/96270, EP-A 731077, DE-A 10211275, DE-A 10131297, WO 99/46039, US-A 4 788 371, EP-A-0 705 136, WO 99/29420, US-A 4 220 091, US-A 5 430 220, US-A 5 877 369, EP-A-0 117 146, DE-A 199 37 196, DE-A 199 37 105, US-A All of the materials set forth in 3, 670, 044, US-A 6, 566, 573, US-A 4, 788, 371, WO 94/29021, and DE-A 199 37 107. In particular, the catalysts of Example 1, Example 2, Example 3 and Example 4 of DE-A 199 37 107 can be used.

The materials are comprised of 10 to 99.9 wt% of zirconium dioxide, 0 to 60 wt% of alumina, ceria and/or titania and 0.1 to 10 wt% of the first or second main group of the periodic table. The dehydrogenation catalyst of at least one element, one of the third transition groups, one of the eighth transition groups, and the dehydrogenation catalyst of tin is limited to a total of 100 wt%.

Typically, the dehydrogenation catalyst can be a catalyst extrudate (typically 0.1 to 10 mm in diameter, preferably 1.5 to 5 mm; typically 1 to 20 mm in length, preferably 3 to 10 mm in length), ingot ( Preferably, the size is the same as the extrudate) and/or the catalyst ring (the outer diameter and length in each case are usually 2 to 30 mm or 10 mm each, and the wall thickness is suitably 1 to 10 mm or to 5 mm or 3 mm). For heterogeneous catalytic dehydrogenation in a fluidized bed (or moving bed), a finer separation of the catalyst should be used accordingly. According to the invention, a fixed catalyst bed is preferred.

In general, dehydrogenation catalysts (especially those proposed in DE-A 199 37107 (especially the exemplary catalysts in this DE-A)) are capable of catalyzing the dehydrogenation of hydrocarbons such as propane. These substances are hydrogen and the combustion of a hydrocarbon to be dehydrogenated, such as propane, with molecular hydrogen. Hydrogen combustion proceeds faster on the catalyst than dehydrogenation of a hydrocarbon to be dehydrogenated, such as propane, as compared to combustion in a competitive situation.

Reactor types and process variants suitable for use in the conventional heterogeneously catalyzed partial dehydrogenation of the present invention for dehydrogenation of hydrocarbons are, in principle, all of the reactors and methods known in the prior art, the conditions being specific The reaction chamber within the reactor satisfies the basic requirements of the present invention. Descriptions of such method variants are for example found in all prior art documents cited with respect to dehydrogenation catalysts and in the prior art described at the outset.

A relatively comprehensive description of a method of a reaction chamber of the invention that is also suitable for conventional heterogeneously catalyzed dehydrogenation (non-oxidative or oxidative), such as in Catalytica Studies Division, Oxidative Dehydogenation and Alternative Dehydrogenation Processes, Study Number 4192 OD, 1993, 430 Ferguson Drive, Mountain View, California, 94043-5272 USA.

The conventional heterogeneous partial catalytic dehydrogenation of a dehydrogenated hydrocarbon such as propane is characterized in that the dehydrogenation step is carried out in an endothermic manner. This means that the heat required to achieve the desired reaction temperature must be supplied to the reaction gas beforehand and/or during heterogeneous catalytic dehydrogenation.

In other words, at least one of the catalyst beds in the reaction chamber having the characteristics of the present invention is passed through the at least one initial gas stream in a single pass, and the reaction chamber can be transported by, for example, the outside of the reaction chamber enclosed by the casing of the present invention. The controlled heat exchange of the hot fluid (ie liquid or gas) is isothermally configured (external control of temperature distribution). A corresponding heat exchanger can also be provided within the reaction chamber itself.

However, based on the above reference, it can also be designed in an adiabatic manner, i.e., there is substantially no controlled heat exchange (external uncontrolled temperature distribution) with the (external) transported heat carrier. In the latter case, the total thermal profile based on a single pass through the reaction chamber of the present invention can be endothermic (negative) by internal control (e.g., by hydrogen combustion in subsequent steps) temperature profile (to be described below). It can be configured either by self-heating (basically zero) or by exothermic mode (positive value).

Generally, as noted above, conventional heterogeneously catalyzed partial dehydrogenation of at least one hydrocarbon to be dehydrogenated (e.g., propane) of the present invention requires a relatively high reaction temperature. The achievable conversion rate is usually limited by thermodynamic equilibrium. Typical reaction temperatures are from 300 to 800 ° C or from 400 to 700 ° C. Dehydrogenation of each mole of, for example, propane to propylene yields one mole of hydrogen. Temperature and H ₂ is removed so that the position of equilibrium toward the reaction product of the desired product as an inert diluent to reduce the partial pressure of the equilibrium position is also moved to the desired product.

Furthermore, the conventional heterogeneously catalyzed partial dehydrogenation of at least one hydrocarbon to be dehydrogenated (for example propane) is characterized in that a small amount of high-boiling high-molecular-weight organic compounds (including carbon) are formed due to the high reaction temperature required. And deposited on the surface of the catalyst to inactivate it. To minimize this disadvantage, the initial gas may be steam diluted, the initial gas comprising a hydrocarbon to be dehydrogenated (e.g., propane) and passed through a catalyst surface at a high temperature by conventional heterogeneously catalyzed dehydrogenation. According to the principle of liquefied gas, the deposited carbon is partially or completely and continuously eliminated under the conditions obtained.

Another way to eliminate the deposited carbon compound is to cause the oxygen-containing gas to constantly flow through the dehydrogenation catalyst at a high temperature, thereby allowing the deposited carbon to be efficiently combusted. However, it is also possible to appropriately inhibit carbon by adding molecular hydrogen to a hydrocarbon to be dehydrogenated (for example, propane) in a conventional manner under heterogeneous catalysis before transporting the hydrocarbon to be dehydrogenated through the dehydrogenation catalyst at a high temperature. The formation of sediments.

It will be appreciated that it is also possible to add a mixture of steam and molecular hydrogen to the hydrocarbon to be dehydrogenated, such as propane, under heterogeneous catalysis. The addition of molecular hydrogen to heterogeneously catalyzed dehydrogenation of propane also reduces the formation of undesirable propadiene, propyne and acetylene as by-products.

Thus, conventional heterogeneously catalyzed dehydrogenation of a hydrocarbon (e.g., propane) (e.g., having a relatively low propane (or general hydrocarbon) conversion) can be suitably performed in a (quasi) adiabatic manner in accordance with the present invention. This means that the initial gas will generally be first heated to a temperature of 400 or 500 to 700 ° C (550 to 650 ° C) (eg by directly baking the wall surrounding it). Typically, during the cooling of the reaction gas from about 30 ° C to 200 ° C (depending on conversion and dilution), a single adiabatic passage through at least one catalyst bed disposed within the reaction chamber of the present invention will suffice to achieve the desired conversion. From the standpoint of the adiabatic method, the presence of steam as a heat carrier is also clearly advantageous. The relatively low reaction temperature allows the life of the catalyst bed used to be extended.

In principle, the conventional heterogeneously catalyzed dehydrogenation of hydrocarbons (e.g., propane) of the present invention (regardless of whether it is carried out adiabatically or isothermally) can be carried out in a fixed catalyst bed or in a moving bed or fluidized bed.

Catalyst feeds suitable for conventional heterogeneous catalytic dehydrogenation of hydrocarbons to be dehydrogenated, such as propane, as described in a single pass through the reaction chamber of the invention, in particular DE-A The catalyst disclosed by the examples in 199 37 107, and mixtures thereof with geometric shaped bodies which are inert to conventional heterogeneously catalyzed dehydrogenation.

After prolonging the operating time, the above-mentioned catalyst can be regenerated in a simple manner, for example by first diluting the air (preferably) with nitrogen and/or steam at the first regeneration stage at 300 to 600 ° C (in extreme cases, even up to The (fixed) catalyst bed is passed at 750 ° C, if appropriate, at an inlet temperature of typically 400 to 550 °C. The catalyst loaded with the regeneration gas (based on the total amount of the regeneration catalyst) may be, for example, 50 to 10000 h ^-1 , and the regeneration gas has an oxygen content of 0.5 to 20% by volume.

In subsequent subsequent regeneration stages, the regeneration gas used under other similar regeneration conditions may be air. It is proposed that the catalyst is suitably flushed with an inert gas (i.e., N ₂ ) from the viewpoint of application before regeneration.

Subsequently, it is usually appropriate to use pure molecular hydrogen or an inert gas (preferably steam and/or nitrogen) under other identical conditions (hydrogen content should be 1% by volume) diluted molecular hydrogen is regenerated.

Dehydrogenation of a conventional heterogeneously catalyzed hydrocarbon (e.g., propane) in the process of the present invention may be carried in a reaction chamber of the present invention with a catalyst supported on an initial gas and a hydrocarbon to be dehydrogenated (e.g., propane) present therein. Low conversion of hydrocarbons (propane) to be dehydrogenated at 100 to 10 000 h ^-1 , usually 300 to 5000 h ^-1 (i.e., 500 to 3000 h ^-1 in many cases) 30 mol%) and high conversion rate ( 30 mol%) to operate.

The conventional heterogeneous catalytic dehydrogenation of at least one hydrocarbon to be dehydrogenated (e.g., propane) of the present invention may be particularly preferred in the tray reaction chamber of the present invention ( 30 mol% and >30 mol% dehydrogenation conversion (for example, 40 mol% or 50 mol%).

The tray reaction chamber of the present invention comprises more than one catalyst bed which is catalytically dehydrogenated in a spatial sequence. The number of catalyst beds may be, for example, from 1 to 20, suitably from 2 to 8, but may also be from 3 to 6. The catalyst beds are preferably arranged in a radial or axial sequence. From the application point of view, the use of a fixed catalyst bed in the tray reaction chamber is suitable.

In the simplest case, the fixed catalyst beds are axially aligned within the reaction chamber or arranged in an annular gap of the concentric cylinder grid. However, it is also possible to arrange the annular gaps in a stack in each of the reaction chambers and in a radial direction through a section and into the adjacent sections above or below them.

Suitably, the reaction gas (initial gas) is subjected to intermediate heating in the tray reaction chamber on the way of a catalyst bed to an adjacent bed, for example by passing it through a heat exchanger rib that is heated by hot gas, or By passing it through a tube heated by hot combustion gases or a heat exchanger plate heated by hot gases.

When the method of the invention is additionally operated adiabatically in a tray reaction chamber, 30 mol% of dehydrogenation conversion (for example propane conversion) (especially when using the catalyst described in DE-A 199 37 107, especially for the exemplary embodiments) is sufficient to transfer the initial gas into the pre-precipitated The reaction chamber is heated to a temperature of 400 or 450 to 550 ° C (preferably 400 to 500 ° C) and maintained within this temperature range in the tray reaction chamber. This means that the entire dehydrogenation reaction of the present invention can therefore be carried out at relatively moderate temperatures, at least in the presence of a new catalyst, which is found to be particularly advantageous for the lifetime between two regenerations of the fixed catalyst bed.

It is preferred to carry out the conventional heterogeneous catalytic dehydrogenation in a substantially self-heating manner in the reaction chamber of the present invention (also as described above), that is, to carry out the above intermediate heating by a direct route (autothermal method).

To this end, a limited amount of molecular oxygen can be advantageously added to the reaction gas as it passes through the reaction chamber of the present invention (eg, after it flows between the first catalyst bed and between the downstream catalyst beds). . Depending on the dehydrogenation catalyst used, hydrocarbons present in the reaction gas, coke or coke-like compounds deposited on the surface of the catalyst and/or hydrogen can be obtained (for example, in conventional heterogeneously catalyzed dehydrogenation (for example) Limited combustion occurs during the formation of propane dehydrogenation and/or has been added to the reaction gas (from the application point of view, the catalyst bed can also be appropriately inserted to feed specifically (selectively) catalyze hydrogen (and / In the tray reaction chamber of the catalyst of the combustion of the hydrocarbons (for example, US Pat. No. 4,788,371, US-A 4, 886, 928, US-A 5, 430, 209, US-A 5, 530, 171, US-A 5, 527, 979 And the materials of US-A 5,563,314; for example, the catalyst beds may be alternately contained in the tray reaction chamber with a bed containing a dehydrogenation catalyst). The heat of reaction released thereby allows the quasi-adiabatic reactor to be configured in a quasi-self-heating manner, in effect an isothermal (internal temperature control) mode of operation for heterogeneously catalyzed (eg propane) dehydrogenation. As the residence time of the selected reaction gas mixture in the catalyst bed is extended, the dehydrogenation (e.g., propane) may therefore be carried out at a reduced temperature or at a substantially constant temperature, resulting in a significant extension of the life span between the two regenerations. .

Conventional non-oxidative heterogeneous catalytic dehydrogenation is a conventional oxidative heterogeneous catalysis from the perspective of the present application by subsequent combustion of molecular hydrogen formed during dehydrogenation as described. Dehydrogenation.

In general, the oxygen feeding is carried out as described above such that the oxygen content in the reaction gas is 0.01 or 0.5 to 30% by volume based on the amount of the hydrocarbon to be dehydrogenated and the dehydrogenated hydrocarbon (e.g., propane and propylene) present therein. Suitable oxygen sources are pure molecular oxygen or molecular oxygen diluted with an inert gas such as CO, CO ₂ , N ₂ , a noble gas, but may especially be air. The resulting combustion gases generally have an additional dilution effect and thus promote heterogeneous catalysis (e.g., propane) dehydrogenation.

Isothermality of conventional heterogeneously catalyzed (e.g., propane) dehydrogenation can be further incorporated by evacuation (equivalent but not necessarily) of the evacuation prior to filling the space between the catalyst beds (e.g., Tubular) internal components to improve. The internal components can also be placed in a particular catalyst bed. The internal components comprise a suitable solid or liquid that evaporates or melts above a certain temperature and consumes heat as it evaporates or melts, and when the temperature drops below this value, condenses again and releases heat as it condenses.

Another way of heating the initial gas or initial gas stream for conventional heterogeneous catalysis (e.g., propane) dehydrogenation to the desired reaction temperature in the reaction chamber of the present invention is by means of molecular oxygen present in the initial gas. When entering the reaction chamber (for example, on a suitable specific combustion catalyst, for example by simply passing over and/or through it), combusting a portion of the hydrocarbon to be dehydrogenated (eg propane) and/or H ₂ present therein And by means of the heat of combustion thus released, it is heated to (dehydrogenation) the desired reaction temperature. The resulting combustion products (such as CO ₂ , H ₂ O, and N ₂ ) that can be accompanied by the molecular oxygen required for combustion are advantageous inert diluent gases.

The above hydrogen combustion can be carried out in a particularly preferred manner as described in WO 03/076370 or DE-A 102 11 275. In other words, in the reaction chamber of the present invention, a continuously oxidative heterogeneously catalyzed partial dehydrogenation of a hydrocarbon to be dehydrogenated, such as propane, wherein: - at least one of the at least one to be dehydrogenated An initial gas stream of hydrocarbon (eg, propane), molecular oxygen, molecular hydrogen, and (if appropriate) steam is continuously fed into the reaction chamber; - in the reaction chamber, the at least one hydrocarbon to be dehydrogenated is transported through at least one disposed a catalyst bed in the reaction chamber, which forms molecular hydrogen on the catalyst bed by conventional heterogeneous catalytic dehydrogenation and at least partially forms at least one dehydrogenated hydrocarbon (for example, propylene); if appropriate, the reaction gas has After entering the reaction chamber of the present invention, other gases containing molecular hydrogen are added to the reaction gas on the way through the reaction chamber; - molecular oxygen in the molecular hydrogen present in the reaction gas is at least partially oxidized to steam, and - continuously withdrawing at least one product gas stream comprising molecular hydrogen, steam, dehydrogenated hydrocarbons (for example propylene) and hydrocarbons to be dehydrogenated (for example propane) from the reaction chamber; wherein it is withdrawn from the reaction chamber of the invention The at least one product stream is divided into two portions of the same composition, and one of the two portions is recycled as a dehydrogenation recycle gas to the at least one initial gas stream fed into the reaction chamber of the present invention, and the other portion is One mode is further used (e.g., for the purpose of heterogeneously catalyzing partial oxidation of dehydrogenated hydrocarbons formed in the reaction chamber).

For example, the product gas for the oxidative or non-oxidative heterogeneous catalytic dehydrogenation of propane to propylene of the present invention may have the following contents: 25 to 60% by volume of propane; 8 to 25% by volume of propylene; 0 to 25 vol% of H ₂ and 0 to 30% by volume of CO ₂ .

In the above discussion, propane has been used in various forms as a heterogeneous catalysis of a hydrocarbon to be dehydrogenated in a conventional non-oxidizing or oxidizing manner. Of course, the procedure can also be applied to all other compounds listed as hydrocarbons to be dehydrogenated at the beginning of the text. In particular, it should be mentioned again that butane (dehydrogenation to butene and/or butadiene; especially isobutane dehydrogenation to isobutylene) and dehydrogenation of butene to butadiene.

Quite generally, at least one initial gas stream of the oxidative or non-oxidative heterogeneous catalytic dehydrogenation of the present invention generally comprises 5 vol% of a hydrocarbon to be dehydrogenated (for example, propane). Furthermore, it may comprise, for example: a) N ₂ and H ₂ O; b) N ₂ , O ₂ and H ₂ O; c) N ₂ , O ₂ , H ₂ O and H ₂ ; d) N ₂ , O ₂ , H ₂ O, H ₂ and CO ₂ .

As mentioned above, in most cases, the method of the present invention is followed by a method of heterogeneously catalyzing partial oxidation of the resulting dehydrogenated hydrocarbon (for example, oxidation of propylene to acrolein and/or acrylic acid), preferably with unconverted The hydrocarbon to be dehydrogenated (for example, propane) is used as an inert gas. From the reaction chamber may be used in the present invention (continuous) extraction of the product gas stream itself or its components removed (e.g. _{H 2, H 2 O, N} 2 , etc.) (except dehydrogenated hydrocarbon (e.g., propylene) and (unconverted a portion of the dehydrogenated hydrocarbon (e.g., propane) is fed to at least one oxidation reactor and subjected to selective heterogeneity of the dehydrogenated hydrocarbon (e.g., propylene) and molecular oxygen present in the feed gas mixture. Catalyzing a partial gas phase oxidation reaction to form a product gas mixture B comprising (partial oxidation products) a target product (eg, acrolein or acrylic acid or a mixture thereof), and generally also comprising unconverted hydrocarbons to be dehydrogenated (eg, propane) Excess molecular oxygen and, if appropriate, unconverted hydrocarbons to be dehydrogenated (for example propylene).

The target product (eg, acrolein or acrylic acid or a mixture thereof) present in the product gas mixture B will be removed in the downstream separation zone B and will comprise from the unconverted hydrocarbons to be dehydrogenated (eg propane), molecular oxygen and ( If appropriate, the residual gas remaining in the unconverted dehydrogenated hydrocarbon (for example propylene) comprises at least unconverted hydrocarbons to be dehydrogenated (for example propane) and, if appropriate, unconverted molecular oxygen and (if appropriate A portion of the unconverted dehydrogenated hydrocarbon (e.g., propylene) gas is recycled to the process of the invention as a partial oxidation cycle gas (e.g., as a component of the initial gas stream).

When the process of the invention is carried out, for example, by conventional oxidative heterogeneously catalyzed partial dehydrogenation of propane to propylene (but may be otherwise) and subsequent partial oxidation of propylene to acrolein or acrylic acid or mixtures thereof, The at least one initial gas stream in the reaction chamber of the present invention may comprise, for example, the following substances as important contents: 0 to 20 or to 10, usually 0 to 6% by volume of propylene; 0 to 1, in most cases 0 to 0.5, usually 0 to 0.25 vol% acrolein; 0 to 0.25, in most cases 0 to 0.05, usually 0 to 0.03 vol% of acrylic acid; 0 to 20 or to 5, in most cases 0 to 3, usually 0 to 2% by volume of CO _x ; 5 to 50, preferably 10 to 20% by volume of propane; 20 or 30 to 80, preferably 50 to 70 5% by volume of nitrogen; 0 to 5, preferably 1.0 to 2.0% by volume of oxygen; 0 to 20, preferably 5.0 to 10.0% by volume of H ₂ O, and 0, usually 0.01, often 0.05 to 10, preferably 1 to 5% by volume of H ₂ .

A small amount (about the equivalent of the possible acrylic acid content) of acetic acid may also be present.

Typically, the target product (eg, acrylic acid) is removed from product gas mixture B by converting the target product (eg, acrylic acid) to a condensed phase. This can be done by absorption and/or condensation (cooling) methods. Suitable absorbents in the case of acrylic acid as the target product are, for example, water, aqueous solutions or especially hydrophobic organic solvents having a high boiling point (boiling point above the boiling point of acrylic acid at 1 atm). More preferably, the conversion to a condensed phase in the acrylic acid state is achieved by stepwise condensation of the product gas mixture B. It is preferred to effect the absorption and/or condensation conversion of the acrylic acid in the product gas mixture B into a condensed phase in a column comprising separate internal components, wherein the product gas mixture is typically transported from bottom to top. The absorbent is typically introduced at the top of the column and the residual gas is typically released from the column at the top of the column.

Further removal of the acrylic acid from the condensed phase is typically accomplished in a desired purity using at least one thermal separation process. It should be understood that this means that they can obtain two different material phases (eg, liquid/liquid; gas/liquid; solid/liquid; gas/solid, etc.) and bring them into contact with each other. Due to the imbalance between the phases, heat transfer and mass transfer occur between the phases and eventually leads to separation (removal). The term "thermal separation process" means that it needs to remove or provide heat to achieve the formation of a phase of matter and/or to remove or provide thermal energy to promote or maintain mass transfer.

According to the invention, the at least one thermal separation process preferably comprises at least one removal from the crystallization of the liquid phase. Suitably, the at least one crystal of acrylic acid is removed as suspended crystals, and the suspended crystals are advantageously pre-removed and in a scrubber column (gravity or mechanical or hydraulic wash column; according to the invention Preferably, the latter is washed by washing the molten crystal. Other suitable thermal separation methods are, for example, extraction, desorption, crystallization, rectification, azeotropic distillation, azeotropic distillation, distillation and/or stripping. In general, pure acrylic acid will be obtained by using a combination of different thermal separation methods of the same materials.

After removing the acrylic acid, a free radical polymerization method (especially for preparing a highly water-absorbing polyacrylic acid and/or a partially or completely neutralized alkali metal (preferably Na) salt thereof) may be carried out, wherein the removed acrylic acid is subjected to Free radical polymerization to prepare a polymer.

It is also possible to carry out a process for preparing an acrylate after removing the acrylic acid, wherein the removed acrylic acid is an alcohol (preferably an alkanol, more preferably a C ₁ - to C ₁₂ -alkanol) (generally under acid catalysis) To esterify.

The esterification process can be followed by a free radical polymerization process in which the acrylate thus obtained is polymerized.

Regardless of the features of the invention of the reaction chamber of the present invention, the process of the invention is known from the preparation of propylene as a source of propylene for its partial oxidation to produce acrolein and/or acrylic acid, which processes include oxidation A circulating gas method for circulating gas and, if appropriate, a dehydrogenation cycle gas. For example, a description of such multi-stage methods can be found in the following documents: DE-A 10 2005 022 798, DE-A 102 46 119, DE-A 102 45 585, DE-A 10 2005 049 699, DE-A 10 2004 032 129, DE-A 10 2005 013 039, DE-A 10 2005 010 111, DE-A 10 2005 009 891, DE-A 102 11 275, EP-A 117 146, US 3,161,670, DE-A 33 13 573, WO 01/96270, DE-A 103 16 039, DE-A 10 2005 009 885, DE-A 10 2005 052 923, DE-A 10 2005 057 197, WO 03/076370, DE-A 102 45 585, DE-A 22 13 573, US 3,161,670 and the prior art described in these documents. DE-A 102 19 686 discloses corresponding procedures in the preparation of methacrolein and/or methacrylic acid.

Detailed descriptions of the absorption and/or condensation methods for converting the acrylic acid from product gas mixture B to the condensed phase are also found in the prior art. This includes the documents DE-A 103 36 386, DE-A 196 31 645, DE-A 195 01 325, EP-A 982 289, DE-A 198 38 845, WO 02/076917, EP-A 695 736, EP- A 778 225, EP-A 1 041 062, EP-A 982 287, EP-A 982 288, US-A 2004/0242826, EP-A 792 867, EP-A 784 046, EP-A 695 736 (especially absorbed) Method) and WO 04/035514, DE-A 199 24 532, DE-A 198 14 387, DE-A 197 40 253, DE-A 197 40 252 and DE-A 196 27 847 (especially condensation methods).

In addition, the description of the absorption and/or condensation removal of acrylic acid from the product gas mixture B can also be found in the following documents: EP-A 1 338 533, EP-A 1 388 532, DE-A 102 35 847, WO 98 /01415, EP-A 1 015 411, EP-A 1 015 410, WO 99/50219, WO 00/53560, WO 02/09839, DE-A 102 35 847, WO 03/041833, DE-A 102 23 058 DE-A 102 43 625, DE-A 103 36 386, EP-A 854 129, US 4,317,926, DE-A 198 37 520, DE-A 196 06 877, DE-A 195 01 325, DE-A 102 47 240, DE-A 197 40 253, EP-A 695 736, EP-A 1 041 062, EP-A 117 146, DE-A 43 08 087, DE-A 43 35 172, DE-A 44 36 243, DE -A 103 32 758 and DE-A 199 24 533. In principle, however, it can also be carried out as described in the following documents: DE-A 103 36 386, DE-A 101 15 277, DE-A 196 06 877, EP-A 920 408, EP-A 1 068 174, EP-A 1 066 239, EP-A 1 066 240, WO 00/53560, WO 00/53561, DE-A 100 53 086, WO 01/96271, DE-A 10 2004 032 129, WO 04/063138, WO 04/35514, DE-A 102 43 625 and DE-A 102 35 847.

When the hydrocarbon to be dehydrogenated for use in the process of the invention is propane, it is preferably fed to the at least one initial gas stream as crude propane, according to the teachings of DE-A 102 45 585.

Generally, the at least one initial gas stream comprises at least 5 volume percent of the hydrocarbon to be dehydrogenated. Usually, the value of this volume ratio is calculated by the corresponding object. 10% by volume, often 15% by volume and often 20% by volume or 25 vol% or 30% by volume. However, in general, the value of this volume ratio is calculated as described above. 90% by volume, usually 80% by volume and often 70% by volume. The above data is particularly applicable to the case where propane is used as a hydrocarbon to be dehydrogenated and propylene is used as a dehydrogenated hydrocarbon. Of course, it is also applicable when isobutane is a hydrocarbon to be dehydrogenated and isobutene is a dehydrogenated hydrocarbon.

Obviously, for the implementation of the conventional (oxidative or non-oxidative) heterogeneous catalytic dehydrogenation of the present invention, especially for the adiabatic mode of operation, the interior of a simple blast furnace ("blast furnace reactor") is sufficient to contain at least one of the at least one A reaction chamber of the invention of a catalyst bed (e.g., the at least one fixed catalyst bed) is flowed axially and/or radially by the initial gas stream.

In the simplest case, it is, for example, a generally cylindrical container having an inner diameter of 0.1 to 10 m, possibly 0.5 to 5 m, and wherein the at least one fixed catalyst bed is placed on a support device (eg, a grid On the grid). The hot initial gas stream comprising the hydrocarbon to be dehydrogenated (e.g., propane) is suitably axially flowed through a reaction chamber fed with a catalyst (the inventive casing is adiabatic during adiabatic operation). The catalyst geometry can be spherical or circular or linear. Since the reaction chambers in the situation just described can be constructed by extremely inexpensive means, all catalyst geometries with particularly low pressure drops are preferred. The catalytic geometry is especially a catalytic geometry or a constructed catalytic geometry that can form a large cavity volume, such as a monolith or a honeycomb. In order to carry out the radial flow of the reaction gas comprising a hydrocarbon to be dehydrogenated, such as propane, the reaction temperature of the invention may, for example, comprise two concentric cylindrical grids, and the catalyst bed may be placed in its annular gap. In the case of adiabatic conditions, the casing (jacket) surrounding it (if appropriate) is also insulated. In the case of a generally cylindrical blast furnace through which the axial flow passes, the dimension A at a right angle to the cylindrical axis of the reaction chamber is at least 5 times, preferably at least 10 times the bed height S of the at least one catalyst bed in the axial direction. More preferably, at least 15 times, the method of the invention is advantageous in the context of an adiabatic mode of operation. However, in general, the above ratio of A:S 200, usually 150 and often 100.

In contrast to the background of the above description, the invention comprises, inter alia, a (material) housing E which is part of the subject matter of the invention, which encloses the inner chamber I (reaction chamber) and has at least one first aperture O1 for at least one gas flow Feeding (the material flow) into the inner chamber I and the at least one second hole O2 to remove (extract) the air flow (material flow) S fed into the inner chamber 1 via the at least one first hole O1 from the inner chamber I, The surface of the housing E on its side contacting the inner chamber I is at least partially made of steel S having the following elements, having a layer thickness d of at least 1 mm: 18 to 30 wt% Cr; 9 to 36 Ni% of wt%; Si of 1 to 3 wt%; N of 0.1 to 0.3 wt%; 0 to 0.15 wt% of C; 0 to 4 wt% of Mn; 0 to 4 wt% of Al; 0 to 0.05 wt% of P; 0 to 0.05 wt% of S; and 0 to 0.1 wt% of one or more rare earth metals; and in addition to, Fe and impurities produced in the manufacture; each percentage is based on the total weight.

Advantageously, the total amount of impurities produced in the manufacture is equivalent to the usual 1 wt%, preferably 0.75 wt%, better 0.5 wt%, and the best 0.25 wt%. However, in general, the total amount of impurities produced in the manufacturing process is 0.1 wt%. A preferred rare earth metal of the present invention is Ce. Therefore, according to the invention, the corresponding steel preferably comprises 0 to 0.1 wt% of Ce or Ce and one or more rare earth metals other than Ce. The chamber I of all the shells E is suitable for carrying out the method of the invention after introducing at least one catalyst bed comprising a dehydrogenation catalyst (especially for the non-oxidative or oxidative adiabatic heterogeneous catalytic dehydrogenation of propane) These methods for propylene).

According to the invention, the surface of the housing E on its side contacting the inner chamber I is advantageously made of a corresponding steel S, the surface thickness d of the finished surface being at least 1 mm, and the surface area produced is the total area thereof. At least 10%, preferably at least 20%, at least 30%, more preferably at least 40%, or at least 50%, more preferably at least 60%, or at least 70%, more preferably at least 80% or at least 90%, and most preferably at least 95% or at least 100%.

According to the invention, the above d is advantageously at least 2 mm, or at least 3 mm, or at least 5 mm. It should be understood that d can also 5 mm to 30 mm, or up to 25 mm, or up to 20 mm, or up to 15 mm, or up to 10 mm. Most preferably, the housing E is made entirely of the steel S of the invention or from at least 80%, preferably at least 90% or at least 95% by weight of the steel S of the invention.

Advantageously, the volume of the inner chamber I (calculated as emptying) is from 5 m ³ to 500 m ³ , typically from 10 m ³ to 400 m ³ , often from 20 m ³ to 300 m ³ , in most cases 30 m ³ to 200 m ³ , or 50 m ³ to 150 m ³ .

Of course, the steel suitable for the steel S of the shell E is also all other steels S of the invention which have been described herein and which are preferred in the above. Advantageously, the steel S is aluminized, aluminized and/or aluminized on its side contacting the inner chamber I.

In particular, the present invention relates to a housing E whose inner chamber I comprises at least one catalyst (dehydrogenation catalyst) suitable for heterogeneously catalyzed partial dehydrogenation of a hydrocarbon to be dehydrogenated. Suitable such catalysts are, in particular, all of the dehydrogenation catalysts detailed herein.

The amount of catalyst present in the chamber of the housing E may be from 100 kg to 500 t (metric tons) or from 200 kg to 400 t, or from 300 kg to 300 t, from 400 kg to 200 t, or from 500 kg to 150 t, Or 1 t to 100 t, or 10 t to 80 t, or 20 t to 60 t. In this context, it does not contain any inert shaped bodies that specifically dilute the catalyst.

The invention further relates to a housing E comprising an inner chamber 1 comprising at least one grid, preferably at least two concentric grids. Advantageously, the housing E has (including) an annular (hollow cylindrical) section R (or portion) (in this case, the inner chamber I _R forms part of the inner chamber I).

If D is one-half the difference between the outer diameter A of the annular section R (calculated irrespective of the outer layer insulation) and the inner diameter R, then the ratio V _{1 of} D to A is preferably 1:10 to 1:1000 according to the invention. , in most cases, 1:20 to 1:800, usually 1:30 to 1:600, in most cases 1:40 to 1:500, or 1:50 to 1:400, or 1:60 It is 1:300, but in most cases it is 1:70 to 1:200, or 1:80 to 1:150.

The ratio of the height H (the distance between the two parallel circular planes defining the annular section R) to A (V ₂ =H:A) V ₂ can be >1 or =1 or <1.

When V ₂ > 1, it is usually from 2 to 10, typically from 4 to 8, and often 6. When V ₂ < 1, it is usually from 0.01 to 0.95, generally from 0.02 to 0.9, often from 0.03 to 0.8, and in most cases from 0.05 to 0.7, or from 0.07 to 0.5, or from 0.1 to 0.4. Therefore, the possible values of V _{2 are} also 0.2 and 0.3.

When V ₂ > 1, A usually 0.5 m to 5 m, typically 1 m to 4 m, and suitably 2 m to 3 m.

When V ₂ <1, A usually 0.5 m to 8 m, preferably 2 m to 6 or 7 m and often 2.5 m to 5 m.

When V ₂ =1, the outer diameter A is usually from 0.5 to 8 m, or from 2 to 6 or m 7, or from 2.5 m to 5 m.

When V ₂ >1, the annular inner chamber (ring inner chamber) of the annular section R of the housing E is particularly suitable for the configuration of the tray reaction chamber of the invention (flowing through in a radial manner) and is particularly suitable The method of the invention. To this end, the annular inner chamber I _R suitably comprises a fixed catalyst bed introduced between the concentric grids, the annular gaps being advantageously arranged in a segmented stack such that the reaction gas flowing therethrough passes through a section in the radial direction Delivered into adjacent segments above or below it. The number of the above-mentioned catalyst beds may be from 1 to 20, preferably from 2 to 8, and preferably from 3 to 6. In other words, it is preferred according to the invention to have a housing E having a ring inner chamber I _R having an annular gap arranged in a segmented stack and consisting of concentric grids in each condition, and the inner chamber V ₂ > 1.

When V ₂ <1, the annular inner chamber (internal chamber) of the annular section R of the housing E is particularly suitable for the configuration of the tray reaction chamber of the invention (which flows in an axial manner) and is particularly suitable In the method of the invention. To this end, the annular inner chamber I _R suitably comprises a catalyst bed introduced into a grid arranged in an axial sequence (i.e., along a ring or cylinder axis) which is successively flowed by the reactive gas. The number of the above-mentioned catalyst beds may be from 1 to 20, preferably from 2 to 8, and preferably from 3 to 6. In general, they are arranged at equal distances.

In other words, according to the invention it is preferred to have a housing E having a ring inner chamber I _R comprising a grid arranged in axial order and having V ₂ <1. When H is 2 m to 4 m (preferably 3 m to 4 m, or 3.5 m) and the inner diameter of the annular section R (at a wall thickness of 1 to 4 cm) is 5.90 m to 6.30 m, V ₂ <1 is especially suitable. The number of catalyst bed trays arranged in the axial order in the above condition is suitably three. The bed of the catalyst bed (e.g., the catalyst of Example 4 of DE-A 10219879) is suitably 10 to 60 cm (e.g., 30 cm).

Suitably, the two parallel circular planes defining the annular section R are in each case defined as a cover (supplemented to form the housing E). In principle, the cover can be in the form of a flat bottom (cover) or curved. According to the invention, a cover which is curved on both sides of the annular section R is preferred. The curved portion may have a quasi-spherical shape as in DIN 28013 or a semi-elliptical shape as in DIN 28011. The curvature of the lower end cap generally points in the opposite direction of the inner chamber I _R (outwardly curved, raised). The curved portion of the upper end cap may be concave or convex relative to the inner chamber I _R . From the application point of view, the simplest way is that both covers are convexly curved with respect to the inner chamber I _R . In this case, the at least one first aperture O1 is suitably located in the center of the upper end cap and the at least one second aperture O2 is suitably located in the center of the lower end cap. The holes O1 and O2 are preferably circular. From an application point of view, its cross section is chosen such that its ratio coincides with the ratio of the expected volume flow through which it flows in and out. When the height H of the annular section is 2 m to 4 m (preferably 3 to 4 m, or 3.50 m) and the inner diameter is 5.90 to 6.30 m, the diameter of the at least one first hole O1 is usually, for example, 1200 mm and The diameter of the at least one second hole O2 is typically, for example, 1400 mm. From the application point of view, the wall thickness of the lower end cover is advantageously thicker than the D of the annular section R. In this case, the portion of the cover wall that protrudes beyond D can carry a grid (and a catalyst bed) in the annular section R, for example, arranged in an axial sequence (one stacked on top of the other).

However, individual annular grids may also be composed (assembled) from the same (individual) circular portion (such as the cross section of a citrus slice). From the application point of view, it is preferably twelve equal parts or eight equal parts or six equal parts or four equal parts or three equal parts circular parts. The circular portion of the grid can in turn rest on the circular portion of the open frame. The circular portion of the lowermost frame is adapted to conform to the curved portion of the lower end cover and is releasable and placed in the convex curved portion of the lower end cover of the element which is the circular portion of the support frame. Then, in various situations, the circular portion of the frame of the grid portion disposed above it can be placed on the portion of the catalyst disk immediately below it.

In principle, the housing E can be produced in a seamless manner from the annular section R and the two closures that terminate it. However, the section R and the cover are typically made separately and then joined together in a substantially airtight manner (leakage <10 ^-4 mbar.l/s). In the case of the lower end cap, this combination with the annular section R is preferably achieved by welding it. However, in the case of the upper end cap, this combination with the annular section R is advantageously achieved by fixing the flange thereof (the removability of the upper end cap makes the loading and removal of the catalyst flexible, for example In the case of partial catalyst replacement, or in the case of all catalyst replacement). It is especially preferred to have a flange joint with a welded lid seal (it is preferred in accordance with the invention that the welded lid seal is preferably made of a steel sheet having a steel S having a thickness of about 2 mm).

Preferably, the shaped contact medium is not placed directly on the grid in accordance with the present invention. The reason for this is that the shaped touch media typically have a size that is smaller than the mesh width of the grid. Therefore, suitably, a layer of talc balls (having a height of 1 to 10 cm, preferably 5 to 10 cm) having a diameter of 3 to 10 cm and a total of 4 or 5 to 8 cm is first placed on the grid ( It is better to use the block talc C220 of CeramTec. In principle, in addition to the outside of the sphere, a shaped body (e.g., a cylinder or a ring) having the longest dimension (the longest line connecting the two points on the surface thereof) conforming to the above diameter is also applicable. Suitable inert materials which may be substituted for the block talc include, in particular, alumina, cerium oxide, cerium oxide, zirconium dioxide, cerium carbide or cerium salts such as magnesium silicate and aluminum silicate. The catalyst bed layer is then applied externally to the inert layer. The reaction gas flows through the reaction chamber in a corresponding manner from above to below. At the top, the catalyst bed is again covered by a suitable inert bed.

The conduit for feeding at least one initial gas stream is typically joined to at least one first orifice O1 by a flange, as is the combination of the conduit for removing at least one product gas stream and the at least one second orifice O2.

For correct and safe operation, the above-mentioned conduits are preferably provided with means for compensating for longitudinal expansion effects, for example due to temperature changes, and it is advantageous to use a compensator which is characterized by a lateral mode.

These compensators, which generally have a multi-layer design, can be made of the same material as the pipe itself. However, particularly advantageous embodiments are those which are preferably made of the steel S of the invention and which have inert tube parts (generally: gas permeable rigid inner tube and gas impermeable elastic outer sleeve (gas impermeable elastic outer) Tube)) which contacts the gas to be transported and suitably has a gas permeable expansion joint and an outer gas impermeable elastic corrugated member, the outer gas impermeable elastic corrugated member being at least partially mechanically compressible and Made of hot pressed material, for example material 1.4876 (according to VdT V-Wb 434 named) or 1.4958/1.4959 (named according to DIN 17459) or INCOLOY 800 H or 800 HT, or nickel based material 2.4816 (instead of named alloy 600) or 2.4851 (instead of named alloy 601).

The volume within the cover can be suitably reduced by means of a displacement body mounted to the inner chamber of the cover to minimize the residence time of the gas fed into the interior of the housing E in an advantageous manner in accordance with the invention.

An alternative to the above solution is to use a concave surface (the inner chamber of the concave annular section R) to bend the cover. In this case, it is advantageous that the at least one hole O1 for feeding at least one air flow into the inner chamber is not mounted at the center of the upper end cover. Further, in this case, suitably, a window which is appropriately evenly distributed, such as the holes communicating with the annular inner chamber I _R , is mounted around the uppermost end portion of the annular section R. Viewed from the outside, the annular groove attached to the window rod in a gastight manner (similar to the annular groove for feeding the salt melted in the salt bath cooling tube bundle reactor; see DE-A 19806810, Figure 1 No. 22) Suitable around the window pole. Next, the initial gas flow is delivered to an annular groove that evenly distributes this gas flow through all of the windows and feeds it into the inner chamber I _R via the window. The impingement baffle can be mounted to the inner chamber I _R , at a controlled distance from the viewing window and additionally to distribute the initial flow of air fed into the inner chamber I _R evenly across the cross section of the inner chamber I _R .

In order to carry out heterogeneous catalytic dehydrogenation of at least one hydrocarbon adiabatic to be dehydrogenated in the inner chamber I of the casing E (especially the inner chamber I _R ), the heat insulating material (=reducing heat from the casing to the environment) The amount of heat transfer material (eg, glass wool, asbestos, and/or ceramic wool) is reversed toward the inner chamber I and mounted to the side of the housing E (including the cover and the feed and removal conduits). If necessary, the above-mentioned heat insulating material may be additionally applied to the side of the casing E facing the inner chamber. In this case, it may itself have, for example, a separate outer casing of the steel sheet of the invention. In summary, the adiabatic is preferably a single pass through the inner chamber I based on the reaction gas during the process of the present invention in the inner chamber I, and the entire inner chamber I is averaged. 10%, preferably 5% and better 2% of the heat content is lost to the external environment of the housing E. In a state in which at least one hydrocarbon adiabatic to be dehydrogenated is subjected to conventional oxidative heterogeneous catalytic dehydrogenation (for example, propane dehydrogenation to propylene), the pipeline is introduced into the inner chamber I via the shell E, containing molecular oxygen (for use) Gases (e.g., air) and, if appropriate, hydrocarbons in the exothermic catalytic combustion of molecular hydrogen can be injected, for example, between the catalyst disks.

As an alternative embodiment, the housing E suitable for use in the method of the invention is also the one described as a hollow sphere. In these situations, the housing E has a hollow ball section K, which is conceivable as a hollow sphere that intersects through two parallel planes. The hollow ball section K is then formed between the two planes, and in each case the hollow ball cap is cut, which can assume the function of the outwardly ending section K of the cover. The chamber I _{K of the} segment K is in turn formed by a particularly relevant portion of the inner chamber I (corresponding to I _R ). In addition, everything about the provision of the catalytic disk and the feed hole O1 and the removal hole O2 for the cylindrical housing E is similarly applicable in the case of the spherical housing E. The description of the insulation is also applicable. It is generally advantageous to mount a support ring around the casing E itself, which is suitably placed on the four supports to hold the casing E.

When the inner chamber I formed by the casing E contains internal members such as a grid, it is preferably also made of the steel S of the present invention. However, according to the method of the present invention, it can also be made, for example, of refractory clay (aluminum silicate) or talc (such as C 220 of CeramTec) or other (substantially inert) high temperature ceramic materials such as alumina, Ceria, cerium oxide, zirconium dioxide, cerium carbide or other cerium salts such as magnesium citrate.

According to the invention, the surface of the housing E is advantageously on at least part of its surface contacting the inner chamber I _R or the inner chamber I _K (or at least 10% or at least 20% or at least 30% or at least 40% or at least 50 % or at least 60% or at least 70% or at least 80% or at least 90% or at least 95% of this portion of the surface, made of the steel S of the invention, having a layer thickness of at least 1 mm (or at least 2 mm) , or at least 3 mm, or at least 4 mm, or at least 5 mm, or 5 mm to 30 mm, or as thick as 25 mm, or as thick as 20 mm, or as thick as 15 mm, or as thick as 10 mm). The section R or section K of the housing E is advantageously made of steel S of the invention of at least 80% or at least 90% by weight, advantageously at least 95% and most advantageously 100%. The discussion of segments R and K also relates to the cover and its inner surface.

When the casing E is made by welding the steel S of the present invention, according to the present invention, the welding is preferably carried out by the same material (i.e., the basic material), and the other welding materials are the same. In principle, it is also possible to use a low melting point steel whose elemental composition is extremely close to the steel S of the invention. Welding is preferably carried out under an inert gas atmosphere (more preferably under argon and/or helium).

Suitable fusion welding methods are electro-optical arc welding of rod electrodes and protective gas welding (especially WIG method). The protective gas used is preferably a nitrogen-containing protective gas. The welding electrode used may be a welding electrode Thermanit D (W 22 12 H) or Thermanit C (W 25 20 Mn) or Sandvik 22 12 HT.

Finally, it should also be noted that the steel S of the present invention not only satisfactorily burns the hydrocarbon to be dehydrogenated and/or the dehydrogenated hydrocarbon completely in the presence of molecular oxygen, but even has a relatively limited catalytic effect.

Examples and comparison examples I. General experiment description

1. Configuration of Reaction Tube The geometry of the reaction tube is: length: 0.55 m; outer diameter (A): 21.34 to 22 mm; wall thickness (W): 2 to 2.77 mm.

The specific reaction tube was filled with an inert sphere made of CeramTec's block talc C 220 over its entire length. The generally evenly distributed sphere has a diameter of 1.5 mm to 2.5 mm.

2. The materials used in the reaction tube are 5 different materials.

Material 1 (M1): Stainless steel of DIN material number 1.4841 (A = 22 mm, W = 2 mm).

Material 2 (M2): Stainless steel of DIN material No. 1.4541 (A = 22 mm, W = 2 mm) having the following elemental composition: 17.31 wt% of Cr; 10.05 wt% of Ni; 0.51 wt% of Si; 0.017 wt% N; 0.042 wt% of C; 1.17 wt% of Mn; 0.025 wt% of P; <0.0005 wt% of S; 0.29 wt% of Ti, and in addition, Fe and impurities produced in the production; The percentages are based on the total weight (test certificate of Sterling Tubes).

Material 3 (M3): Stainless steel of DIN material No. 1.4541, but with a surface aluminized towards the side of the reaction chamber (A = 22 mm, W = 2 mm).

Material 4 (M4): Aluminized aluminum nitride (A = 22 mm, W = 2 mm).

Material 5 (M5): stainless steel of the invention having the following elemental composition (A = 21.34 mm, W = 2.77 mm): 20.87 wt% of Cr; 10.78 wt% of Ni; 1.54 wt% of Si; 0.161 wt% of N; 0.082 wt% of C; 0.75 wt% of Mn; 0.02 wt% of P; 0.0026 wt% of S; 0.05 wt% of Ce, and in addition, Fe and impurities produced in the production, each percentage is Total weight.

3. The following initial gas stream for the typical composition of the propane for the heterogeneous catalytic dehydrogenation of the present invention to propylene is fed to different reaction tubes: feed A: 31.7 vol% propane; 51.0 vol% N ₂ ; 3.09 % by volume of O ₂ ; 6.33 vol% of H ₂ and 7.88 vol% of H ₂ O; feed B: 33.8 vol% of propane; 54.5 vol% of N ₂ ; 3.3 vol% of O ₂ and 8.4 vol% of H ₂ O.

Feed C: 33.8 vol% propane; 57.8 vol% N ₂ and 8.4 vol% H ₂ O.

In all cases, the selected propane load for the fixed bed of inert talc balls was chosen to be 20 l(STP)/l. h.

4. In each case, the reaction tube system was installed in a radiant furnace (an electrically heated ceramic body having a hollow cylindrical guide rod that can accommodate the reaction tube, and a gap width of 0.2 cm between the hollow cylindrical guide rod and the outer wall of the reaction tube).

5. The specific reaction tube is passed through a specific initial gas stream as described (in this case this has an inlet temperature of 200 °C). At the same time, the temperature T ^{A of the} outer wall of the reaction tube is increased, so that the maximum temperature T ^M in the reaction tube is raised from 400 ° C to 700 ° C in a substantially linear manner at a gradient of 10 ° C / h (this simulation is increased in continuous operation) Compensation for the catalyst bed that is inactivated by temperature).

Subsequently, the regeneration of the dehydrogenation catalyst bed was simulated. To this end, 420 ml (STP)/min of N ₂ at an inlet temperature of 200 ° C was first passed through the reaction tube while maintaining the temperature T ^M at 700 ° C.

While maintaining the temperature T ^M =700 ° C, the following gas circulation plan was operated: - a mixture of air (85.4 ml (STP) / min) and N ₂ (341.6 ml (STP) / min) after 60 min) Then, after 60 min, 417 ml (STP) / min of air; followed by 15 min, 417 ml (STP) / min of N ₂ ; followed by 60 min, 168 ml (STP) / min of H ₂ .

Next, the specific reaction tube through which the specific feed flows is passed from T ^M =700 ° C to T ^M =400 ° C in a generally linear manner with a T ^M gradient of 10 ° C/h.

Depending on the feed materials and reaction tube materials may be used, at 500 ℃, 600 ℃, 650 ℃ and temperature of 700 deg.] C or less measured value T ^A N ^P (%) (at the beginning of the reaction tube, (by vapor phase layer Analysis) continuously analyzing the composition of the leaving gas stream); determining the total amount of by-product N ^P of the hydrocarbons other than propane (methane, ethane, and ethylene), based on the total amount of carbon fed into the reaction tube, expressed as The total carbon content of the total amount of hydrocarbon by-products, such as propane (in %): feed A

Feed B

Feed C

U.S. Provisional Patent Application Serial No. 60/751,973, filed on December 21, 2005, is incorporated herein by reference.

In connection with the above teachings, the invention can be varied and deviated.

Thus, it is contemplated that the invention may be practiced otherwise than as specifically described herein within the scope of the appended claims.

Claims (48)

A method for continuous heterogeneously catalyzed partial dehydrogenation of at least one gas phase hydrocarbon to be dehydrogenated, comprising a process in which a reaction chamber is closed by a casing, the casing and the reaction chamber Contacting and having at least one first orifice for feeding at least one initial gas stream into the reaction chamber and at least one second orifice for withdrawing at least one product gas stream from the reaction chamber, the process comprising the following: - continuous Feeding at least one initial gas stream comprising at least one hydrocarbon to be dehydrogenated; - in the reaction chamber, passing the at least one hydrocarbon to be dehydrogenated through at least one catalyst bed placed in the reaction chamber, with concomitant production a product gas comprising the at least one dehydrogenated hydrocarbon, the unconverted hydrocarbon to be dehydrogenated, and the molecular hydrogen and/or vapor, partially dehydrogenated to at least one dehydrogenated hydrocarbon in an oxidative or non-oxidative manner, and - at least one product The gas stream is continuously withdrawn from the reaction chamber, wherein the surface of the shell contacting the side of the reaction chamber is at least partially made of steel S having the following elements, and is formed to have a layer thickness d of at least 1 mm: 18 to 30 wt. %Cr;9 36wt% of Ni; 1 to 3wt% of Si; 0.1 to 0.3wt% of N; 0 to 0.15 wt% of C; 0 to 4 wt% of Mn; 0 to 4 wt% of Al; 0 to 0.05 wt% of P; 0 to 0.05 wt% of S; and 0 to 0.1 wt% of one or more rare earth metals; and in addition to, Fe and impurities produced in the manufacture, each percentage being based on the total weight. The method of claim 1, wherein the steel S has the following elemental composition: 20 to 25 wt% of Cr; 9 to 20 wt% of Ni; 1.4 to 2.5 wt% of Si; 0.1 to 0.3 wt% of N; 0.03 to 0.15 wt. % of C; 0 to 3 wt% of Mn; 0 to 4 wt% of Al; 0 to 0.05 wt% of P; 0 to 0.05 wt% of S; and 0 to 0.1 wt% of one or more rare earth metals; and in addition to, Fe and impurities produced in the manufacture, each percentage being based on the total weight. The method of claim 1, wherein the steel S has the following elemental composition: 20 to 22 wt% of Cr; 10 to 12 wt% of Ni; 1.4 to 2.5 wt% of Si; 0.12 to 0.2 wt% of N; 0.05 to 0.12 wt. % of C; 0 to 1 wt% of Mn; 0 to 2 wt% of Al; 0 to 0.045 wt% of P; 0 to 0.015 wt% of S; and 0.03 to 0.08 wt% of Ce or Ce and one or more rare earth metals; and in addition, Fe and impurities produced in the production, each percentage being based on the total weight. The method of any one of claims 1 to 3, wherein the hydrocarbon to be dehydrogenated is a C ₂ to C ₁₆ alkane. The method of any one of claims 1 to 3, wherein the hydrocarbon to be dehydrogenated is at least one hydrocarbon selected from the group consisting of ethane, propane, n-butane, isobutane, n-pentane, and different Pentane, n-hexane, n-heptane, n-octane, n-decane, n-decane, n-undecane, n-dodecane, n-tridecane, n-tetradecane, n-pentadecane and n. alkyl. The method of any one of claims 1 to 3, wherein the hydrocarbon to be dehydrogenated is ethane, propane, n-butane and/or isobutane. The method of any one of claims 1 to 3, wherein the hydrocarbon to be dehydrogenated is propane and the dehydrogenated hydrocarbon is propylene. The method of any one of claims 1 to 3, wherein the initial gas stream comprises steam. The method of any one of clauses 1 to 3, wherein the initial gas flow comprises Oxygen. The method of any one of claims 1 to 3, wherein the catalyst bed is a fixed catalyst bed. The method of any one of claims 1 to 3, wherein the surface of the shell contacting the side of the reaction chamber is made of steel S having a range of at least 10% of its total surface area and a layer thickness d of at least 1mm. The method of any one of claims 1 to 3, wherein the surface of the shell contacting the side of the reaction chamber is made of steel S having a range of at least 50% of its total surface area and a layer thickness d of at least 1mm. The method of any one of claims 1 to 3, wherein d is at least 3 mm. The method of any one of claims 1 to 3, wherein d is at least 5 mm. The method of any one of claims 1 to 3, wherein at least 80% of the weight of the casing is made of steel S. The method of any one of claims 1 to 3, wherein the housing is made entirely of steel S. The method of any one of claims 1 to 3, wherein the heterogeneously catalyzed partial dehydrogenation is non-oxidative dehydrogenation. The method of any one of claims 1 to 3, wherein the heterogeneously catalyzed partial dehydrogenation is oxidative dehydrogenation. The method of any one of claims 1 to 3, wherein the heterogeneously catalyzed partial dehydrogenation is heterogeneously catalyzed oxidative dehydrogenation. The method of any one of claims 1 to 3, wherein the heterogeneously catalyzed partial dehydrogenation is a conventional heterogeneous catalytic dehydrogenation of adiabatic. The method of any one of claims 1 to 3, wherein the heterogeneous catalytic portion Dehydrogenation is a conventional heterogeneously catalyzed partial dehydrogenation and the reaction chamber is a tray reaction chamber. The method of claim 21, wherein the conventional heterogeneously catalyzed partial dehydrogenation is oxidatively known as heterogeneously catalyzed partial dehydrogenation. The method of claim 22 is carried out in an adiabatic manner. The method of any one of claims 1 to 3, wherein the initial gas flow fed to the reaction chamber comprises: 0 to 20% by volume of propylene; 0 to 1% by volume of acrolein; 0 to 0.25 vol% of acrylic acid; 0 to 20% by volume of CO _x ; 5 to 50% by volume of propane; 20 to 80% by volume of nitrogen; 0 to 5% by volume of oxygen; 0 to 20% by volume of H ₂ O; 0 to 10% by volume of H ₂ . The method of any one of claims 1 to 3, wherein the product gas stream withdrawn from the reaction chamber is used directly, or at least a component other than the dehydrogenated hydrocarbon and the hydrocarbon to be dehydrogenated is removed. After a portion, it is fed into at least one oxidation reactor, and the dehydrogenated hydrocarbon present therein is subjected to selective heterogeneously catalyzed partial gas phase oxidation with molecular oxygen in the oxidation reactor to generate Product gas mixture B of a partial oxidation product. The method of claim 25, wherein the hydrocarbon to be dehydrogenated is propane, the dehydrogenation The hydrocarbon is propylene and the partial oxidation product is acrolein, acrylic acid or a mixture thereof. The method of claim 25, wherein the partial oxidation product is subsequently removed from the product gas mixture B in the separation zone B of the selective heterogeneously catalyzed partial gas phase oxidation, and the unconverted is removed from the inclusion In the residual gas of hydrogen hydrocarbon, molecular oxygen and any unconverted dehydrogenated hydrocarbon, at least a portion of the hydrocarbon containing unconverted to be dehydrogenated is recycled as a partial oxidation cycle gas to the hydrocarbon to be dehydrogenated. Heterogeneously catalyzed partial dehydrogenation. The method of claim 27, wherein the portion of the oxidation product in separation zone B is removed from product gas mixture B by conversion to a condensed phase. The method of claim 28, wherein the partial oxidation product is acrylic acid and the conversion to a condensed phase is achieved by an absorption and/or condensation process. The method of claim 29, wherein the removing the acrylic acid from the condensed phase is carried out using at least one thermal separation method. The method of claim 30, wherein the at least one thermal separation method comprises removing acrylic acid from the liquid phase crystallization. The method of claim 31, wherein the crystallization is removed by suspension crystallization. The method of claim 30, wherein the acrylic acid is removed after the removal of the acrylic acid, wherein the removed acrylic acid is radically polymerized to prepare a polymer. The method of claim 30, wherein the method of preparing an acrylate is carried out after relaying the acrylic acid, wherein the removed acrylic acid is esterified with an alcohol. The method of claim 34, wherein the method of relaying the acrylate is further advanced A radical polymerization method is carried out in which an acrylate thus prepared is polymerized. a housing E enclosing an inner chamber I and having at least one first hole O1 for feeding at least one gas stream S into the inner chamber I, and at least one of which is fed into the inner hole O1 in advance via the at least one first hole O1 a second hole O2 drawn from the inner chamber I, the surface of the housing E contacting the inner chamber I is at least partially made of steel S having the following elements, the layer thickness d being at least 1mm: 18 to 30 wt% of Cr; 9 to 36 wt% of Ni; 1 to 3 wt% of Si; 0.1 to 0.3 wt% of N; 0 to 0.15 wt% of C; 0 to 4 wt% of Mn; 0 to 4 wt% of Al; 0 to 0.05 wt% of P; 0 to 0.05 wt% of S; and 0 to 0.1 wt% of one or more rare earth metals; and in addition thereto, having Fe and impurities produced in the production, each percentage being based on the total weight, and the inner chamber I containing at least one dehydrogenation catalyst. The housing E of claim 36 has an inner chamber 1 containing at least one grid. The housing E of claim 36 has an annular section R. The casing E of claim 38, wherein the ratio V ₁ =D:A formed by one half D of the difference between the outer diameter A and the inner diameter of the annular section R is 1:10 to 1:1000. The housing E of claim 39, wherein V ₁ is 1:40 to 1:500. The housing E of claim 38, wherein the ratio V ₂ = H: A is > 1 formed by two distances H between the parallel circular planes defining the annular section R and the outer diameter of the annular section. The casing E of claim 38, wherein the ratio between the distance H between the parallel circular planes defining the annular section R and the outer diameter of the annular section is V ₂ = H: A 1. The housing E of claim 36 has a hollow ball section K. The housing E of claim 36 has a thermally insulating material on its opposite side facing the inner chamber 1. A method of heterogeneously catalyzing partial dehydrogenation of a hydrocarbon, which is carried out in a chamber I of a casing E according to any one of claims 36 to 44. Use of a shell E according to any one of claims 36 to 44 for heterogeneously catalyzed partial dehydrogenation of hydrocarbons. The method of any one of claims 1 to 3, wherein the steel S has been aluminized, aluminized and/or aluminized on its side contacting the reaction chamber. The housing E of claim 36, wherein the steel S has been aluminized, aluminized and/or aluminized on its side contacting the inner chamber 1.